neurotransmitter
nounA chemical substance, such as acetylcholine or dopamine, that transmits nerve impulses across a synapse.
nounAny 
a neurochemical that transmits nerve impulses across a synapse
A chemical substance, such as acetylcholine or dopamine, that transmits nerve impulses across a synapse.
nounAny 
a neurochemical that transmits nerve impulses across a synapse